1. Field of the Invention
The present invention relates to a device search apparatus and method for searching, via a network, for a device such as an image forming apparatus, and relates to a device search server, a device search system, and a storage medium.
2. Description of the Related Art
Heretofore, a device such as an image forming apparatus can be utilized from a client PC via a network. At that time, the client PC is required to search for and find the device on the network and install driver software for using the found device.
As a technique to perform such processing, WSD (Web Services on Devices) has been proposed by Microsoft Corporation, in which a WS-Discovery specification is used to search for a device on a network. A device search system has also been proposed, in which a client PC sends by multicast a request for device search to a DP (discovery proxy) server and the DP server sends back a search result that includes device information held in the DP server. Further, in a WS-Discovery specification recommended by the OASIS (Organization for the Advancement of Structured Information Standards), a method is defined in which a client PC sends a request for DP server search to a DP server that sends back a search result including DP server information held therein.
Meanwhile, with the progress of network technologies, it becomes possible to construct a large scale network by connecting networks together using routers or other connection devices. In such a network, routers are generally utilized in settings that prevent broadcast and multicast from passing through the routers since broadcast and multicast can affect traffic in the entire network. Specifically, broadcast and multicast are generally utilized only within each of subnets (i.e., networks that are partitioned from one another by the routers).
With conventional network device search technologies where multicast is used, a search request packet transmitted from a client PC is unable to pass through routers in most cases, and it is therefore difficult for the client PC to find a device on a different subnet in a network environment including a plurality of subnets connected together by routers. To solve such a problem, there has been proposed a technique in which servers are provided for respective subnets, and device information and search requests are exchanged between the servers (see, for example, Japanese Laid-open Patent Publication No. 2007-97057).
With the proposed technique, however, each server is required to transfer a client PC's device search request to the server on different subnet, and also required to transfer to the client PC a search response sent back from the server on different subnet in reply to the request for device search.
Since each server automatically transfers a request for search to the server on predetermined different subnet, a problem is posed that the client PC cannot select the server on a subnet on which a device to be searched for is present.